Self-packing pipe joint



Aug 8, 1950 A. c. ISCHER 2,517,778

SELF-PACKING PIPE JOINT Filed May 51, 1945 Patented Aug. 8, 1950 UNITEDSTATES '1=A'rr.1\1T

f OFFICE SELF-PACKING PIPE JOINT Albert C. Fischer, Chicago, Ill.Application May 31, 1945, Serial No. 596,853

1 Claim.

This invention relates to packings for sealing the joints between pipesections which, as in the case of bell and spigot joints, for instance,are assembled telescopically; and particularly packings comprising two.concentric annular members of plastic material, which are mounted, theone as alining Within the bell, and the other ias a facing, upon thespigot, and which, as the pipe sections are brought together, seattelescopically, one Within the other, and, by iilling the annular spacebetween the overlapping faces of the pipe sections, eiect a gas andliquid tight sealing of the joint.

This invention presents an improvement over the joining of pipe sectionsdisclosed in my earlier Patent No. 2,359,755, October 10,1944, as wellas the numerous molding and joining expedients for pipe sections bymeans of plastic liners dating back to the last century and exemplifiedin many patents of the prior art.

It is the object of the present invention to simplify the joiningoperation by molding the internal annular liner on the bell end of thepipe and the external annular liner on the spigot end of the pipe ofdifferent plastic compositions of such a nature that sealing contact maybe made between them without the need of extraneous solvent or adhesiveagents. This objective is at tained by the molding of one of the sealingliners, preferably the internal one in the bell end of the pipe section,of a permanently tacky and adhesive plastic composition which entersinto effective coalescing relationship with the cooperating sealingliner upon the end of the other pipe section by the mere juncture of thetwo sealing liners as one is telescoped into adhesive contact with theother.

Other objects and purposes will appear from the following detaileddescription of the invention taken in conjunction with the accompanyingdrawing showing in vertical cross-section a preferred embodimentthereof.

In the drawing is shown the lower pipe section II having the bell endthereof internally coated with a sealing liner I3 of a rubberizedbituminous composition, known in the trade as Para-Plastic material,possessing special properties. This annular liner I3 is adapted tocooperate with the sealing liner I2 of plain asphaltic material upon theexternal surface of the adjoining pipe section I0. Lateral surface I5 ofthebell end liner I3 corresponds to the lateralsurface offthe spigot endliner I2 so that as the two pipe sections are telescoped one within theother, these surfaces `come into close contact and result in acoalescence of the material in the liners I2Iandl3. I l

The liners may be moldedin any manner practiced in the prior art, forexample, as practiced inrny patent mentioned above, No. 2,359,755, or inthe Jonhston patent, No. 2,284,741, June 2, 1942, and others. I

The essential improvement in the joining *o `pipes presentedherein is inthe utilization of different plastic compositions `for thetwo liners inorder to eliminate the necessity for the use'of solvents, adhesives orrejuvenating agents upon the plastic liners in order to enable them toenter into tight coalescing relationship. The use of the specialrubberized bituminous composition for one of the sealing liners isresponsible for this simplification. This composition is a tackyadhesive mass having 'a high degree of `distendalcility and recuperativepowers, which properties are not affected by temperatures as low as 10F.

The rubberized bituminous composition, known in the trade asPara-Plastic material, may be compounded of different ingredients and indifferent quantities, in dependence upon the specific applications inwhich the same may be used. These compositions and their modes ofcompounding are disclosed in detail in copending applications Serial No.471,503, iled January 6, 1943; No. 575,935, filed February 2, 1945 whichhas matured into Patent No. 2,511,830, issued June 20, 1950; and No.583,174, filed March 16, 1945. Examples of such compositions are alsodisclosed in my prior Patents 2,368,650 dated February 6, 1945,2,431,384, 2,431,385 and y2,431,386 each dated November 25, 1947, and2,454,506 dated November 23, 1948.

As disclosed in the iirst application above, Serial No. 471,503, thecomposition may consist of about 312% to 5% of rubber, 35% of a hardbrittle asphalt having a melting point of about 170 F. to 180 F., 1/% to1% of a plasticizing agent, about 40% of a Soft lasphalt having a flowpoint of about F., 5% to 7% of a mineral filler and 1% to 3% of a flowretarder.

As disclosed in the second application above,

Serial No. 575,935, the composition may have a polymerized linseed oilin lieu of the rubber con'- stituent, and contains the followingingredients in the specific quantities and broad ranges outlined below:

Percent Percent Kempol #54 32.6 (26 to 35) Trumbull asphalt B 38.0 (35to 45) Servicised flux (residual asphalt oil) 21.6 (16 to 25) Clay 4.0Sto Asbestos 1.1 (0.5 to 1.5)

Zonolite (exfoliated mica) 2.7 (1.5 to 3.5)

In the last mentioned application above, Serial No. 583,174, thecomposition is disclosed as composed of the following ingredients:

Percent Percent Reclaimed rubber 17.5 (12 to 20.0) Flux Oil 3.8 lto10.0) Cumar 1.5 lto y5.0) G. R. S 4,7 2te 10.0) Oil (S. V. superiorbase) 20.0 (13 to 23.0) Resin 7.5 2te 12.0) Asphalt 45.0 (40 to 50.0)

The above composition may Abe poured hot to form the liners as shown inthe patents above, or in any other different ways. Any type of asphalticcomposition known in the trade as hard asphalte may be poured hot toform the sealing liners l2. While it is preferable that the Para-Plastic composition be poured into the bell end of the pipe section inview of the protection aflforded by the internal space in the bell end,it is possible Vto form the Para-Plastic liner on the spigot end of thepipe section, but in such cases 'some extraneous form of protectionwould be desirable,v and for this reason it is not as preferable as thearrangement shown in the drawing.

The ingredients of the Para-Plastic composi tion are such as to maintainthe same in a tacky and adhesive state and which react upon the hardasphaltic composition l2 following the juncture of the two so thatshortly thereafter a tight coalescent joint between the sealing linersis attained.

While I have described my invention as embodied in a specific forni andas operating in a specific manner for purposes of illustration, itshould be understood that I do not limit my invention thereto, sincevarious modifications will suggest themselves to those skilled in theart without departing :from the spirit of my invention, the scope ofwhich is set forth in the annexed claim.

I claim:

In a pipe joint between the bell end of one pipe and the spigot end ofan adjoining pipe, sealing elements comprising an annular liner ofrubber ized bituminous composition of normally tacky and adhesivecharacteristics upon one pipe end and an annular liner of normallynon-tacky bituminous material upon the other pipe end capable ofblending with said tacky composition on pressure contact therewith toform the seal, said liners merging into coalescing relationship upon thetelescoping of one end relative to the other one.

ALBERT C. FISCHER.

REFERENCES CITED The following references are of record `in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 157,356 Stanford Dec. 1, 1874:1,881,438 Fischer Oct. 11, 1932 1,979,470 Johnston Nov. 6, 1,9342,162,687 Fischer June 18, 1939 2,285,046 Murdock June 2, 1942

